Africa's AIDS pandemic may not have been fueled mainly by sexual transmission of HIV but by unsafe medical injections and blood transfusions, a team of international researchers said Thursday. The findings contradict widely held views about how HIV has spread through Africa. Most scientists believe heterosexual sex spreads HIV in up to 90% of adult cases in sub-Saharan Africa, which has 30 million HIV-positive people. But a team of eight experts from three countries that reviewed data on HIV infection in Africa estimate that only about one third of adult cases are sexually transmitted. They said unsafe health care practices, especially contaminated medical injections, could also be a major cause of infection.

"The idea that sex explains 90% of African HIV just doesn't fit the facts," said David Gisselquist, a Pennsylvania-based independent consultant and member of the research team. "Every year there are hundreds of millions of unsafe injections in Africa where needles have been used on someone and reused without sterilization." Three scientists who reviewed the study data agreed that the spread of AIDS in Africa has not followed a pattern expected to be seen with a sexually transmitted disease and said that contaminated needles or contaminated blood could account for many, if not most, of the HIV infections in sub-Saharan Africa.

But the study, published in the U.K. Royal Society of Medicine's International Journal of STD & AIDS, was dismissed by several top AIDS researchers, who said that while some HIV infections in Africa were caused by contaminated needles, most are still transmitted through unprotected sex. "The idea that dirty needles or blood transfusions are the main route for HIV transmission in Africa today flies in the face of experience on the ground," said Chris Ouma, head of health programs at the charity ActionAid Kenya. "In Kenya, medical procedures have largely been made safe, but still HIV infections continue to rise." Some AIDS experts also fear the study will make Africans afraid to visit local clinics and hospitals because of concerns that they will be infected through contaminated needles.

The World Health Organization and the Joint United Nations Programme on HIV/AIDS will hold a meeting in Geneva on March 13-14 to address the issue of unsafe injections.